Thirty-three articles were included in our review [32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64] (see Fig. 1). An overview of the characteristics of included studies is provided in Table 3. Studies included in our realist review were judged on their rigour, i.e. whether we considered the reported method used to generate the piece of data credible and/or trustworthy [21]. The overall quality of included studies varied: 21 studies were rated as high, eight studies as medium and four as low quality (see Table 3).

Fig. 1

Overview of search results

Table 3 Characteristics of included studiesCMOCs and programme theory

Individual leadership skills influenced by interventions were grouped into four categories (see Table 4) and Table 5 provides an overview of the 19 CMOCs we identified through our analysis of all the included articles. Our final programme theory, which encompasses all CMOCs, is provided in Fig. 2. Across the 19 CMOCs, the outcome is the same: improved leadership by an individual as defined in the study (see Table 4 for definitions by study), however context and mechanisms differ. The CMOCs have been grouped into three core areas which improve leadership, those which focus on (1) feedback and how feedback is delivered to those partaking in leadership development, (2) the characteristics of the person or people undergoing leadership development, and finally (3) atmosphere, which represents the physical and psychological environment in which leadership development takes place. We now describe each of our 19 CMOCs in turn, with examples from the evidence provided.

Fig. 2

Final programme theory. The Foundational Model of Surgical Leadership Improvement

Table 4 Outcomes of leadership interventions grouped into cognitive skills, interpersonal skills, business skills, and strategic skillsTable 5 Context-mechanism-outcome configurations with example quotesCMO1-2: timeliness of feedback

The timeliness of feedback was found to be an important contextual feature, which leads to the improvement of leadership. For example, Somasundram et al. (2018) showed that immediate critique from consultants after scenario simulations (referred to as ‘freeze-frames’) were effective for improving participants’ leadership learning [60]. This was echoed by Vu et al., who found that delayed feedback was perceived as limited in its usefulness to residents changing their leadership behaviour [63]. Stakeholders suggested that timely feedback is required because it makes feedback feel relevant and focused, as it is fresh in the memory of the learner. Additionally, a study on debriefing suggested that if feedback on identified problems was provided in a timely manner, surgeons’ faith in the interventions increases, as participants feel satisfied seeing their problems recognised and prioritised [34]. This additional mechanism resonated highly with our stakeholders.

CMO3: reoccurrence of feedback

Evidence suggests that for feedback to improve leadership, it needs to be provided more than once [42, 43, 59, 63]. For example, studies on feedback interventions identified that follow-up feedback should be provided in the form of a survey within 3–6 months [42]. In support of this, Vu et al. (2020) stated that only frequent feedback can lead to behaviour change [63]. A study on mentoring found that those who had weekly, or monthly mentor meetings were most satisfied with their mentoring arrangements [43]. Since mentors provide feedback we felt that this was supporting the other studies. According to Gregory et al. repeated feedback reinforces leadership improvement overtime [42]. After deliberation with stakeholders, “reinforcement of learning” was agreed as the mechanism.

CMO4: feedback delivery by a trusted, respected person

Several studies suggest that feedback delivery through a trusted, respected person is an important context for improving the leadership of surgeons [42, 57, 63]. Several studies mentioned the need for an objective person to deliver feedback [57]. or a trained mentor or coach as a suitable and preferred person to provide feedback to surgeons [42, 63]. However, when discussing this with our stakeholders, they concluded that the most important aspect of a person delivering feedback is that you trust and respect them, as this reciprocal relationship makes you want to improve and maintain that person’s trust and respect. We then noted that excerpts revealed that coaches need to be “more experienced or reputable” (Pradarelly, 2016), indicating that trust and respect are key when delivering feedback.

CMO5: feedback from a range of trusted and respected people

We found that obtaining feedback from a range of people, for example from junior residents, advanced practitioners and nurses [63], is crucial in improving leadership and important in the views of surgeons [42, 63]. Gregory et al. state that feedback from a range of people ensures both comprehensive and diverse feedback. When exploring studies which investigated how mentoring can advance leadership, we found that having multiple mentors appears important in improving leadership for surgeons [36, 49]. However, we found no explicit explanation in the mentorship literature as to why multiple mentors is effective. Stakeholders agreed that obtaining feedback from a range of people can be helpful as it provides a broader picture of yourself. However, stakeholders emphasised that feedback is only helpful in improving leadership if it comes from trusted and respected people. We adapted the CMO to reflect stakeholders’ considerations.

CMO6: delivery of anonymous feedback from juniors to seniors

Gregory et al. [42] found that anonymous feedback helped improve leadership as it allowed surgeons to focus more on feedback content, rather than its source. Stakeholders felt that anonymous feedback had a role to play but only in the context of juniors providing feedback to seniors. Stakeholders felt that this would allow juniors to provide honest feedback as they feel safe to speak their mind. We have specified the context and mechanisms accordingly.

CMO7: delivery of direct feedback from a peer or someone more senior

As outlined in the previous CMO, stakeholders felt that feedback was most effective in improving leadership if it was provided directly (rather than anonymously) from a peer or someone more senior. They reasoned that if feedback is provided from someone at your level or above, (i.e. consultant to consultant) you would want to maintain their trust and working relationship and therefore, improve your leadership skills.

CMO8-9: openness to self-improvement

Our stakeholders suggested that openness to self-improvement is an important mechanism in several contexts. In line with this, two studies indicated that negative feedback is delivered best in a private context [37, 53]. Essentially, surgeons and trainees feel that it is important that they are not challenged or humiliated in front of their peers or colleagues. The private context seems to increase an openness to self-improvement via leadership. In contrast, those who were criticised in front of peers, for example of their handling of surgical cases/at a trauma meeting, were less willing to take on similar cases again in the future or speak openly in meetings because of how it made them feel. In a study on mentoring, we discovered peer-to-peer approaches were more likely to positively impact leadership development [41]. We found that peer-to-peer communication tended to use non-hierarchical language which may have facilitated positive reciprocal reactions to leadership development and a sense of openness between participants. Our stakeholders felt as though the same mechanism (feeling open to and recognising the importance of self-improvement) may be at work here.

CMO10: awareness for the need for leadership skills

The timing in professional career was an important context for improving leadership. Jaffe et al. [47] describe that leadership training was more effective at point of transition, where it was becoming necessary for surgeons to take on leadership roles to continue to progress, for example when surgeons were moving into a surgeon consultant or surgical director role. Stakeholders confirmed that those who are aware that they need leadership capabilities may feel and be more motivated to improve as the intervention is perceived as more relevant for them. This was particularly poignant when surgeons felt that they lagged behind their peers in this regard.

CMO11: having confidence in technical skills

Evidence suggests that leadership interventions are more effective in improving leadership of those with more confidence in their technical skills [47, 54]. Surgeons with more confidence in their technical surgical skills were able to focus on their leadership abilities in simulation training. Those with less confidence in their technical skills were facing the dual challenge of focusing on both technical surgical skills and leadership skill development [54]. The timing of leadership development appears relevant to effectiveness, with those surgeons with more confidence in their technical skills perhaps being more likely to benefit from leadership interventions. Stakeholders agreed with this CMO.

CMO12: having identified leadership deficits

We found evidence to suggest that those who were identified as having leadership deficits, via feedback interventions, demonstrated more improvement in leadership compared to their competent colleagues [42, 45]. Stakeholders suggested that those with identified deficits have more room to improvement and may be more motivated to improve, again elements of peer comparison were mentioned as important.

CMO13: a variety of interactive learning activities

Studies evaluating leadership courses found that variation in the component leadership learning activities was important for improving leadership [44, 47, 57, 62]. Vitous et al. indicate that broad learning activities, such as team building, business acumen, and self-awareness, expand surgeons’ perspectives. Learning activities included business school principles, leadership in the healthcare context, self-empowerment, and economic forces such as understanding financial statements [47, 57, 62]. We found that active reading, reflection and discussion appeared to be learning activities which improved leadership development specifically [44]. Stakeholders agreed that a variety of learning activities are important but stressed that they needed to be interactive to engage participants.

CMO14: implementation of speak-up culture

Brindle (2018) found that if all members of a surgical team were allowed to speak-up, about errors for example, this led to an improvement in communication and improved sense of collective leadership [34]. In support of this, Jayasuriya-Illensghe et al. (2016) found that if junior surgeons and nurses are not encouraged to speak up this leads to communication breakdown between surgical teams [48]. Stakeholders agreed that a speak-up culture was a highly important context, whether that be speaking up about unacceptable behaviour style or technical errors. Stakeholders felt that the mechanism at work was “feeling equally valued and a sense of engagement”. Therefore, highlights the importance of considering the organisational culture in which leadership development takes place.

CMO15: customisation to surgeons’ needs

Evidence from the literature suggests that leadership interventions are effective in improving surgeons’ leadership skills if they are customised to individual surgeons’ needs [53, 57, 59]. For example, studies showed that mentoring and coaching were more effective where surgeons were able to self-select their mentor [53, 59]. A study of a leadership development programme found that intervention effectiveness was dependent on whether the content was personalised to participants and considered their feedback [57]. Mutabzic et al. indicated that ‘sense of control’ over leadership development was the reason why customisation was deemed important in the design of leadership interventions [53]. However, our stakeholders felt that it was less about a ‘sense of control’ but more about the sense of relevance if interventions are customised, and surgeons or surgical trainees had a say in choosing what they felt was most important to them. We therefore adapted this CMO mechanism.

CMO16-17: safe learning environment

Evidence suggests that interventions improve leadership if they occur in a more intimate learning environment, meaning interventions delivered in person and in small groups or one-to-one. For example, mentoring studies showed that surgeons preferred one-on-one and face-to-face meetings, rather than larger group sessions [39, 59]. Similarly, studies of leadership courses and simulation training indicated that small group learning was preferred by participants [44, 60]. According to Hill et al. intimate learning environments increase participants’ willingness to share personal examples, which may encourage and reinforce their learning as they are actively engaging in the subject matter [44]. Our stakeholders reflected that these environments create a sense of ‘safe space’ where surgeons can speak openly to colleagues. Stakeholders also felt it allows participants to apply the learning to their personal context. We felt that both mechanisms were plausible and recognised both.

CMO18: training in surgical teams

Stakeholders stated that it would be important for surgical teams to be given time to train in leadership together and to run through operations together to reinforce learning in practice (the opportunity required in AMO theory). Our stakeholders stressed that leadership is a process and only through training together could you build trust, rapport, friendship, and mutual respect leading to surgical team leadership.

CMO19: genuine investment in the intervention

The concept of ‘genuine investment’ was important for leadership development. We found that if surgeons deem an intervention important in context, and delivered for ‘the right reasons’, then it was more likely to be successful in impacting leadership [34, 36]. For example, mentors who were perceived to be unselfish, and who did not show any tangible benefits from offering mentoring, appeared to positively impact mentee’s leadership development [36]. We found when executive staff were present in the operating room, in a supportive capacity, this signalled to the surgical team members a genuine investment in the leadership intervention [34]. Ramjeewon et al. (2020) affirmed that genuine investment in terms of provision of a realistic setting in simulation studies led to improvement in leadership [58]. This rang true with our stakeholders who concluded that the genuine investment triggered a sense of faith and engagement in the intervention, and in the people delivering it. This led to increased commitment in the programme, and ultimately improvement in leadership.